McConnells Mill State Park is a 2,546 acres (1,030 ha) Pennsylvania state park in Perry and Slippery Rock Townships, Lawrence County, Pennsylvania in the United States. The park features a deep scenic gorge with the restored watermill and a covered bridge at the bottom, accessible by a roadway that winds between large, room-sized boulders on the hillside. McConnells Mill State Park is along the Slippery Rock Creek just southwest of the intersection of US 422 and US 19.McConnells Mill State Park was chosen by the Pennsylvania Department of Conservation and Natural Resources (DCNR) and its Bureau of Parks as one of "Twenty Must-See Pennsylvania State Parks".
There are several trails in the park, including a pair that lead to a waterfall (with an old limestone kiln next to it). The trail system is part of the North Country Trail, the nation' longest National Scenic Trail which runs from North Dakota to New England. There are two Climbing/Rappelling areas. Both are only recommended for "equipped and experienced climbers". The more difficult of the two is at Breakneck Bridge.